Drilling rigs are used to form wellbores for the purpose of extracting oil, natural gas or other fluids from subsurface deposits. Drilling rigs can also be used for sampling subsurface mineral deposits, testing rock or ground fluid properties and for installing subsurface utilities, instrumentations, tunnels or wells. In implementation, drilling rigs may be mobile equipment transportable by truck, rail, trailers, or similar, rigs may also be semi-permanent and permanent fixtures as in the case for oil drilling of large wells. Marine-based structures are also widely known. Generally, the term drilling rig refers to an arrangement of equipment that is used to penetrate the subsurface of the earth's crust.
A conventional drilling rig 30 is illustrated in FIG. 7, where the drilling rig 30 includes a derrick 14, which provides a support structure for a majority of the equipment used to raise and lower drillstring 25 into and out of a wellbore. The drillstring 25 may be an assembled collection of drillpipe, drill collars, or any other assembled collection of assorted tools and equipment connected together and run into the wellbore to facilitate the drilling of a well. The drillstring 25 may be raised and lowered into an dout of the wellbore by the draw-works 7, which includes a spool powered by a motor or other power source 5. A drill line 12, which may be a thick, stranded metal cable, is run through a travelling block 11. Typically, the crown block 13 remains stationary while travelling block 11 moves vertically with the drillstring 25. The combination of the crown block 13 and the travelling block 11 provides a significant mechanical advantage for lifting the drillstring 25. Further, a swivel 18 may be attached to the travelling block 11 to allow rotation of the drillstring 25 without twisting the travelling block 11. Drill pipes 16 and hole casing 26 are also shown.
The drilling rig 30 further includes a rotary table 20 mounted in a rig floor 21, which is used to rotate the drillstring 25 along with a kelly drive 19. Kelly drive 19, attached at an upper end to the swivel 18 and at a lower end to the drillstring 25, is inserted through the rotary table 20 to rotate the drillstring 25 (drillstring rotation shown by arrow “R”). Kelly drive 19 may be square, hexagonal, or any other polygonal-shaped tubing and is able to move freely vertically while the rotary table 20 rotates it. Alternatively, drilling rig 30 may include a top drive (not shown) in place of kelly drive 19 and rotary table 20. Additionally, blowout preventers (“BOPs”) may be located below the rig floor 21 and installed atop a wellhead 27 to prevent fluids and gases from escaping from the wellbore. An annular BOP 23 and one or more ram BOPs 24 are shown and are commonly understood in the art.
During drilling operations, drilling fluid may be circulated through the system to carry cuttings away from the bottom of the wellbore as drilling progresses. Drilling fluid may be stored in mud tanks 1 before being drawn through suction line 3 by mud pumps 4. Drilling fluid (drilling fluid route is indicated by arrows “F”) is then pumped from mud pumps 4 through a hose 6, up a stand pipe 8, through a flexible hose 9, and down into the wellbore. Drilling fluid returning from the wellbore is routed through a flow line 28 to shakers 2, which are used to separate drill cuttings from the drilling fluid before it is pumped back down the wellbore.
Drilling operations typically occur during daylight hours and visibility in and around the drilling rig has historically only been required when manual work is being done, inspection and calibration, for example. There is a desire to increase productivity by providing visibility during hours of low daylight, and this has thus far been accomplished by providing mobile lighting arrangements on vehicles proximate the drilling rig, or otherwise manually adding impromptu lighting arrangements.
These arrangements are inadequate and not readily adaptable to systematic visibility improvements in appropriate locations around a drilling rig.